The rate of AED use in the elderly nursing home population exceeds 10 % yet, the rate of AED use of epilepsy is highest in the elderly and the group of people 65 years of age and older is the most rapidly growing segment of the U.S. population. No research has been reported describing the epidemiological rates of AED use or whether or not AEDs are prescribed differently for subgroups of patients in the elderly by age, sex, or racial groups; nor is it known what outcomes such as basic activities of daily living are associated with the use of AEDs. The focus of this project is on the pharmacoepidemiology of AED use among those who are nursing home residents and will use a population of over 65,000 patients in managed care nursing home settings. The specific aims are: 1) to determine the prevalence of a documented diagnosis of epilepsy or seizures and patient characteristics associated with use of antiepileptic drug (AED) treatment by nursing home residents; 2) to determine the prevalence of and patient characteristics associated with AED monotherapy and polypharmacy among nursing home residents 3) to determine for a cohort of nursing home admissions the AED prevalence upon admission and incidence following admission, the diagnostic and patient indicators of use, and the dosage and duration of treatment during their first year of nursing home residency; and 4) to determine patient outcomes associated with AED treatment in a cohort of nursing home admissions. This is a 5 year collaborative study among faculty at the University of Minnesota. The project's multidisciplinary team includes the disciplines of psychology, pharmacy, biostatistics, and neurology. Primary and secondary source data will be obtained from Beverly Enterprises, a for-profit nursing home chain based throughout the U.S. Data will include automated files of prescription drugs, and clinical, and sociodemographic characteristics of patients serviced from the MDS (Minimum Data Set) which is collected uniformly across the U.S. The results of this health services research study of antidepressant treatment will have implications for decision-making by primary care physicians, neurologists, patients and their families, health care organizations, and policy makers at the state and federal levels, who presently leave little information regarding this vulnerable population.